An active heterocyclic unite building represented by 1,3,4-Thiadiazole-2,5-dithiole (1) was prepared through the reaction of carbon disulfide and hydrazine hydrate .This unite building was reacted with hydrazine hydrate to afford the corresponding 2,5-dihydrazino -1,3,4-thiadiazole(2)which then undergoes one-pot catalyst-free multicomponent reaction with malononitrile, substituted aldehyde and ethyl acetoacetate to obtained 2,5-di(3-methyl-4-aryl-pyrano[2,3-c]pyrazole-5-amino-6-cyno-1-yl)-1,3,4-thiadiazole (3-9). All prepared compounds were elucidated by available methods represented by M.P,T.L.C,FT-IR and for some compounds 1H.NMR.